fix: skip max discount validation for rate adjustment
diff --git a/erpnext/controllers/selling_controller.py b/erpnext/controllers/selling_controller.py
index dc49023..c8d40ed 100644
--- a/erpnext/controllers/selling_controller.py
+++ b/erpnext/controllers/selling_controller.py
@@ -28,7 +28,8 @@
 	def validate(self):
 		super(SellingController, self).validate()
 		self.validate_items()
-		self.validate_max_discount()
+		if not self.get("is_debit_note"):
+			self.validate_max_discount()
 		self.validate_selling_price()
 		self.set_qty_as_per_stock_uom()
 		self.set_po_nos(for_validate=True)